Switching from AP to PA projection reduces gonadal dose. Which option reflects this statement?

• A. AP
• B. PA
• C. AP oblique
• D. PA oblique

Answer: (B)

Switching from AP to PA reduces gonadal dose because the X-ray tube is moved to the opposite side and the gonads lie farther from the source. In a PA setup, the beam must travel through more tissue before reaching the anterior gonads, and the distance from the tube to the gonads is increased, so the dose to those organs drops according to the inverse square law and tissue attenuation. Oblique positions change the path length and dose distribution in less predictable ways, so they don’t reliably minimize gonadal exposure. Therefore, the PA projection reflects this statement.